Media hype about mass shootings in America has fostered a myth that the killings are on the rise and that an assault weapon ban, expanded background checks and greater attention to the mentally ill will curb a rampaging epidemic, according to an authoritative and exhaustive study by a noted criminologist.

Instead, according to James Alan Fox, author and criminology professor at Northeastern University, mass shootings have remained stagnant over 34 years, averaging 20 a year, and few were committed by the type of berserk psychos portrayed by the media.

“Public discourse is grounded in myth and misunderstanding about the nature of the offense and those who perpetrate it,” he writes in the journal “Homicide Studies.” He added: “Without minimizing the pain and suffering of the hundreds of those who have been victimized in recent attacks, the facts clearly say that there has been no increase in mass shootings and certainly no epidemic.”

The study debunks several proposals aired from President Obama, Vice President Joe Biden and Senate Democrats after the December 2012 Sandy Hook Elementary School shooting aimed at stopping mass killings. While he said any plan is worth trying, he concluded that short of abolishing the Second Amendment, there is little that can be done.

“Mass murder just may be a price we pay for living in a society where personal freedom is so highly valued,” he wrote in the study coauthored Northeastern criminology student Monica DeLateur.

They reviewed years of mass shootings and found that most shooters are not the crazed killers pictured on TV: Most are seeking revenge and practice their crime, like the two Columbine, Colo., killers.

“The rarest form of mass murder is the completely random attack,” said the study, “Mass Shootings in America: Moving Beyond Newtown.”

He addressed 10 myths fostered by the press. Key among them:

— Mass shootings are on the rise. He used FBI statistics and found they have long averaged in the 20s per year, rarely going over 25.

— Video games play a role. The study found no link between video games and expanded violence, and blamed the media and lawmakers for using the entertainment industry as a “convenient scapegoat.”

— Profiling will help catch killers before they act. The study found that most are white and about 30 years old, characteristics that “are fairly prevalent in the general society.”

— Expanded background checks will stop killers from getting guns. The study cites a study from former New York Mayor Michael Bloomberg’s Mayors Against Illegal Guns that in 93 recent mass shootings, the gun buyers didn’t have a criminal or mental health record. “People cannot be denied their Second Amendment rights just because they look strange or act in an odd manner,” wrote Fox and DeLateur.

— An assault weapons ban would work. They found that the typical weapon used is a pistol, not an “assault weapon” like the semi-automatic AR-15 rifle. Assault weapons were used in 24.6 percent of mass shootings, handguns in 47.9 percent. And limiting the size of magazines weapons can carry wouldn’t help, they said, because any ban would impact new sales and “there is an ample supply of large capacity magazines already in circulation.”